Method of calcining and clinkering cement-forming materials



Nov- 2 1926. 1,605,279

' R. D. PIKE METHOD OF CALCINING AND CLINKERING CEMENT FORMING MATERIALS Original Filed July 5, 1922 2 Sheets-Sheet 1 is N a; A TTORN E YS Nov. 2 1926. 1,605,279

R. D. PIKE METHOD OF CALCINING AND CLINKERING CEMENT FORMING MATERIALS Original Filed July 5, 1922 2 Sheets-Sheet 2 INVENTOR. -RZ/ i/ZR BY Mwr 4 ATTORNEYS.

that the charged from the Patented Nov. 2 1926.

UNITED STATES 1,605,279 PATENT OFFICE.

ROBERT D. PIKE, OF SAN FRANCISCO, CALIFORNIA.

METHOD OF CALCINING AND CLINKERING CEMENT-FORMING MATERIALS.

Original application filed July 5, 1922, Serial No. 572,895. Divided andthis application filed June 13,

10 after discharged from the calcining apparatus, and a cooling element associated with the discharge end of the clinkering element for receiving the clinker discharging therefrom, the association of the parts being such gaseous products discharging from the clinkering member flow directly into the calcining element or member of the apparatus at substantially the zone of combustion therein, the heated air from the cooling l0 element discharging directly into the clinkering elementto aid in the support of combustion therein. The products of combustion, or the air received into the clinkering element from the cooling element and disclinkering element with its products of combustion directly into the calcining element for supporting combustion therein, and carries therewith the CO gas resulting from the burning of the fuel inthe clinkering element or member of the apparatus, with the result that pure air is not discharged into the calcining member for supporting combustion therein and as substantially all of the air for supporting combustion in the calcining member of the apparatus is required to pass through the rotary clinkering member thereof, of necessity the clinkering member must be of a diameter larger than that required for mere clinkering purposes.

I have discovered that if the air passing through the cooling member or element of the apparatus be directed mainly to the combustion zone of the calcining member orelement of the apparatus, and only sufficient quantity of such air bepermitted to enter the clinkering member or element as will support necessary combustion therein and the products of combustion from said clinkering member or element be delivered to the calcining member or element at a point beyond the zone of combustion therein, that the flame temperature of combustion for the calcining member will be higher and the thermal efliciency thereof will be greater by Serial No. 645,166.

and such smaller diameter clinkering mem- .55

her results in more eflicient heat transfer from flame to clinker and in a smaller loss by radiation to the outside. The methodinvention therefore resides in utilizing a portion of the preheated air discharging from the cooling element of the apparatus for supporting combustion within the clinkering element and directing another portion thereof as pure heated air to the zone of combustion for the fuel within the calcining element or member.

An eflicient and practical apparatus for the carrying out of the present method invention is disclosed in the accompanying sheets of drawings, wherein Fig. 1 is a broken side view in elevation disclosing the associated elements of the apparatus in assembled position.

Fig. 2 is a part broken vertical sectional view taken through the calcining element of the apparatus for disclosing the interior arrangement thereof and the disposition of the annular flue relative to said element for discharge of the heated air of the cooler ontoand over the lower hearth of the said calcining element.

Fig. 3 is a part broken sectional lan view taken on the irregular line A B, ig: 2 0f the drawings.

Fig. 4 is a sectional the line C-C, Fig. l of the drawings.

ig. 5 is a Vertical central sectional view of the cooler, showing means for agitating the material which passes therethrough.

In the drawings, designate any suitable form of a vertically disposed calcining stationary element or member of the apparatus employed for the preliminary treatment of the material to be calcined and rotary element of the apparatus which is employed for the clinkering ofthe calcined material delivered thereto as discharged from the calcining element, and 3 designates the cooling element of the apparatus, which 119.

or element of the apparatus to the 0 thereof to plan view taken on the numeral 1 is used to clinkered; 2 designates the is situated in a plane below the clinkering member 2 and is provided with rabbles 3' for mechanically agitating the material which is passing therethrough.

The cooling member 3 receives the hot clinkered material discharging from the rotary clinkering element or member 2. In the present case, the member 1 is constructed as a multiple hearth mechanically rabbled calcining structure for the preliminary treatment of the material, which is fed therein by any suitable form of a feeder 4. The said element 1 is provided with a series of burners 5 for the use of gaseous, liquid or pulverized fuel, which burners are situated adjacent the lower portion of the element 1 for directing flames onto and over the lower hearth of the said calcining member 1. There is interposed between the upper end of the rotary member 2 and the bottom of the member 1 a receptacle 6, which provides a receiving chamber (3' into which the products of combustion from the member 2 discharge, the said products of combustion escaping or flowing from the chamber 6' through the fines or conduits 7 which communicate with the vertically disposed flues 9 of the calcining member 1; the products of combustion moving upwardly through the flues 9 and escaping therefrom through the outlets 10 into the calcining member 1 and over the hearths therein at points above the zone of combustion of the said member 1. The calcined material discharging from the stationary calcining member 1 moves through the downwardly extended water cooled conduit 11 and discharges therefrom into the upper end of the rotating clinkering member 2. In the lower end of clinkering member 2 is extended a burner 12 for gaseous, liquid or powered fuel, the said burner being extended into a firing hood 13 which surrounds the lower end of the member 2, but does not rotate therewith. There is a suitable running joint provided between the said firing hood 13 and the lower end of the rotating clinkering member 2 and the upper end of said member 2 is similarly connected with the receptacle 6 of the chamber 6. As the calcined material flows through the rotating member 2 it is subjected to the heat of the flame fromthe burner 12, and as the path of travel through the member 2 is a prolonged one, the material flowing therethrough is fully clinkered before discharge therefrom. The clinkered material discharging from the lower end of the downwardly inclined rotary clinkering member 2 passes through a downwardly extended flue 14, and is delivered therefrom in the cooling member 3, which member may be of any suitable structure. In my Patent No 1,557,873 the cooling member is illustrated as a rotary one, while in the present case such member is illustrated of a form corresponding to that of the calcining member 1, and is therefore adapted to subject the material to agitation during the cooling operation thereof, thereby effecting an etlicient transfer of heat from the clinkercd material to the secondary air. As the material flows downwardly through the cooling member 3 and is agitated by the movement of the rabbles therein the same is subjected to a counter-flowing stream of cold air passing thercthrough and admitted thereto through the nozzle or air inlet 15, the cooled clinkered material discharging from the cooler 3 through the discharge spout 16, provided with a suitable seal 16. It will be understood that the air admitted into the cooler 3 through inlets 1:") may be introduced by internal draft or supplied thereto by any suitable form of a power blower. There is extended from the cooler 3 a small conduit 18 which conveys the heated air from the cooling chamber into the tiring hood 13 of the rotary clinkerer 2 for supporting combustion of the burner 12, the said conduit 18 being supplied with a damper control 19. By this means the air for supporting combustion in the rotary clinkering member is supplied in a preheated form from the cooler 3. There is also extended from the cooler 3 a conduit 20 provided with a damper control 21 and with a hopper bottom 21 for collecting dust which may he carried over by the air current from the cooler, the discharge end of conduit 20 communicating with an annular fine 22 surrounding the lower end of the calcining element 1. The heated air of the cooler admitted into the said annular flue 22 discharges therefrom through a plurality of flues 23 extended therefrom for conveying the air onto and over the lower hearth arranged within the calcining element 1 for supporting combustion of the fuel used therein for calcination. In this manner, the air for supporting combustion is delivered as pure air to the zone of combustion of the calcining member 1, and said air is free of the CO gas which is mixed with the products of combustion discharged from the rotary clinkering member 2, and which products of combustion do not enter the calciner or calcining member 1 until after combustion has occurred or taken place therein.

By discharging the products. of Combustion from the rotary or clinkering element 2 into th calcining element 1 at points above the zone of combustion, all heat of such products of combustion is utilized in the calcining element without the CO contained therein retarding combustion in the said element 1. Inasmuch as the heated secondary air for supporting combustion of the fuel is delivered from the cooling member 3 to the zone of combustion of the calcining element 1 as pure air, the flame temperatiu e mary air to distinguish from the hot within the calciner will be higher and the thermal efficiency therefore greater than if even a small percentage of CO is mixed with the air.

By the secondary use of the described apparatus for the carrying out of my method invention, all .heat units contained in the air passing through the cooling element of th e apparatus are conserved and utilized to support combustion of the fuel employed in connection with the calcining element and the rotary clinkering element of the apparatus, only such portion of said air is delivered as pre-heated pure air to the com bustion zone of the calcining element which is required for supporting combustion of the fuel used therein, while the hot products of combustion from the rotary clinkering element are delivered into the calciner element at points situated above the combustion zone of said element so as not to retard combustion in the calciner by reason of the CO contained therein. By reason of the invention permitting of the use of rotary clinkering element of small diameter and which is determined by the amount of gas rather than the amount of clinker which must be passed, there is not only a more eiii cient heat transfer from the flame to the clinker, but smaller losses by radiation to the outside atmosphere.

The method invention resides in utilizing the pre-heated secondary air discharging from the cooler for the clinkering material to support combustion for the fuel of the clinkering element and the calcin- 'ing element, directing a portion of such air direct to the zone of combustion for the fuel of the clinkering element and another portion thereof as pure heated air to the zone of combustion for the fuel of the calcining element, and delivering the products of combustion from the clinkering element in the calcining element at points above its zone of combustion.

The word secondary as employed herein has the usual meaning employed in furnace design and distinguishes the air which may be preheated from that air which is usually employed for atomizing oil or blowing pulverized coal into the furnace and which must be cold for mechanical reasons. The air used for blowing a gas producer is usually cold and is referred to as prisecondary air is used forcompleting the combustion of producer gas when this fuel is employed.

In my present application the calcining member 1 as illustrated is designed for firing with pulverized or atomized fuel over the bottom hearth, but I could employ a method of firing covered in my Patent No.

1,557,873, in which the fuel in the form ofbroken coal is introduced into the calcining element in a zone about midway between the top and bottom. In such event the combustion zone of the calciner is considerably lengthened, and the gases from the rotary clinkering chamber could be introduced in the upper region of the combustion zone while the heated secondary air Would-be introduced in the lower or final zone of combustion.

The herein method invention is fully set forth and described in my pending application Ser. No. 572,895 filed in the United States Patent OfiiceJuly 5, 1922 and allowed under date of April 23, 1923 Patent No. 1,557,873 for improved apparatus for calcining and clinkering, and in which application reservation for the filing of application covering the method invention the-rein described is expressly reserved.

For convenience, the first step of the treatment of the material under my method invention may be said to reside or comprise the passing of material to be treated through a heated calcining zone, such being the moving stream of combustion flowing through any suitable form of a calcining structure; the second step comprising passing the calcined material through a clinkeringzone of higher temperature, such being the stream of combustion flowing through the clinkering structure; the third step residing in passing the clinkered material through the cooling zone of a. cooling structure and during the flow movement thereof passing cooling air therethrough counter-wise to the flowing body of clinkered material, and finally delivering the preheated air from the cooling zone into the calcining zone for supporting combustion therein.

The material undergoing treatment as advanced through the calcining zone and equally so, through the cooling zone, is maintained under agitation and as the movement of the clinkered material under agitation through thecooling zone is a retarded one, ample opportunity is given for the counterflowing body of air passing therethrough to absorb heat from the hot clinkered material and it is such preheated air as is .delivered into the zone of calcination for supporting combustion therein.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. The method of calcining and clinkering material of the character mentioned, which consists of passing the material through a calcining chamber, thence through a clinkering chamber and thereafter passing the hot clinkered material through a cooling chamber, subjecting such hot clinkered material to agitation in the cooling chamber, and passing substantially all of the secondary air needed for supporting combustion in both the calcining and clinkering chambers through said cooling chamber While the material therein is being agitated so as to absorb sensible heat therefrom.

2. The method of calcining and clinkering material of the character mentioned, which consists of passing the material through a calcining chamber, thence through a clinkering chamber and thereafter passing the hot clinkered material through a cooling chamber, subjecting such hot clinkered material to agitation in the cooling chamber, and passing substantially all of the secondary air needed for supporting combustion in both the calcining and clinkering chambers through said cooling chamber While the material therein is being agitated so as to absorb sensible heat therefrom, and directing a portion of this preheated air to the elinkering chamber and the remainder to the calcining chamber Without prior inter-mixture with gases of combustion from the elinkering chamber.

3. A method of calcining and clinkering material of the character mentioned Which consists of passing the material through a calcining chamber, thence through a clinkering chamber introducing undiluted air into the lower portion of the calcining chamber to support combustion therein and passing the hot gases of combustion from the clinkering chamber into the calcining chamber above the zone of introduction of said undiluted air.

4. A method of calcining and clinkering material of the character mentioned which consists of passing the material through a calcining chamber, thence through a clinkering chamber and thereafter through a cooling chamber passing air through the cooling chamber to absorb sensible heat from the hot clinkers therein, passing a portion of the heated air from the cooling chamber to the clinkering chamber for supporting combustion therein, passing the remainder of the heated air from the cooling chamber directly to the combustion zone of the calcining chamber and passing the hot gases of combustion from the clinkering chamber into the calcining chamber above the zone of introduction of said heated air.

In testimony whereof I have signed my name to this specification.

ROBERT D. PIKE. 

